Devices that dispense water from pre-filled bottles are common, but providing such devices with refills poses several problems. Replacing a water bottle always involves some possibility of spillage while removing a partially empty bottle and inverting a full replacement bottle. Because a gallon of water weighs over eight pounds, transporting a bottle containing water sufficient to last a reasonable time, say five gallons, is not trivial, particularly when the bottle must be carried up stairs or for an appreciable distance. Also, a water bottle must be turned upside down and hoisted on top of the typical water dispenser, a difficult task for a person of slight build. Constant replacement of water bottles therefore presents frequently recurring opportunities for injury and spillage. Payne, in U.S. Pat. No. 5,971,220, addressed the replacement problem with an invention for assisting in the inversion and lifting of a replacement bottle, but did not alleviate the need for replacement of a bottle when it has been emptied.
Another concern of consumers of bottled water is that they have no convenient means of being assured of the purity of the water they drink. Pluta (U.S. Pat. No. 6,354,344) discloses disposable and replaceable filters that offer some water treatment, but his invention does not affect the need for replacement of empty bottles.
Sutera (U.S. Pat. Nos. 5,368,197, 5,114,042, and 4,923,091) discloses a self-filling bottled-water cooler conversion kit that addresses the problem of frequent replacement of supply bottles. The Sutera invention utilizes a conventional mechanical float mechanism typically seen in water troughs and commodes. The Sutera float valve is prone to the same frequent failures associated with the water trough and commode valves. Moreover, the float is a large device which most consumers will consider unsightly and even unsanitary when viewed inside a bottle of drinking water. Sutera concedes his invention's aesthetic shortcoming by describing a transparent float (column 7, line 23 in the '042 patent; column 7, line 34 in the '197 patent).
Fridman (U.S. Pat. No. 5,111,966) discloses a cabinet that dispenses water from a constant supply through an inverted water bottle. Hidden inside the Fridman cabinet below the first container bottle is a small second container within a third container. As does Sutera, Fridman depends on a mechanical float valve that operates inside the third container. Fridman also employs a sensor that monitors the head pressure in the bottle and opens and closes a supply valve accordingly. Fridman's design does not accommodate an existing bottled water dispenser; it requires an internal reservoir-within-a-reservoir that completely supplants the internal reservoir of a conventional water dispenser.
For water and juices, aesthetics plays a part in dispenser design. Many consumers prefer to see the water and juices they drink coming from a clear bottle rather than from the types of industrial water coolers that merely pipe a supply of fluid through a refrigeration unit inside a cabinet. Therefore, it is desirable to provide a combination of a constant fluid supply means with the aesthetics of a container in which the fluid is visible.